Formed in 1896, the Brooklyn Rapid Transit Company acquired and consolidated many various train and streetcar services in Brooklyn and Queens. By the time this map was created in 1912, the company owned all but two of the independent transit services in Brooklyn. Each of these lines represented either elevated or surface-level trains and streetcar lines. The company would open its first subway line under 4th Avenue in 1915, eventually running over the Manhattan Bridge. That tunnel is now served by the D, N, R and W lines.